Increases in both the quantity and complexity of information relatingto the field of transcription and transcription factors has led to needs for development of specialized databases that maintain and organize this information. Since the first release of the TranscriptionFactors Database (TFD) in 1990, a number of different developmentsand improvements have been made, including the addition of new tables,internal cross-references, and cross-references to other molecularbiology databases, and an initial set of cross-references to a databaseof eukaryotic promoters (EPD). The database is being used as material for various software development efforts within and outside NCBI. Further research and development plans for this database would include: (a) improved database design, including testing of normalization methods and object-oriented design approaches (b) development of query and retrieval tools for database mining and exploration, the use of these novel as well as existing database exploration tools, including computational analysis of database nucleic acid and amino acid sequences, toward the aim of identifying previously unknown rules or relationships.